Precipitous Deterioration of Motor Function, Cognition, and Behavior.

A 72-year-old woman developed new-onset depression, sustained an unexplained fall, and started walking cautiously. After 1 year, her depression resolved but she developed a dry cough. One year later, she experienced a more rapid decline in her gait with parkinsonism, visual difficulties with restricted vertical gaze, slowed horizontal and vertical saccades, dysphagia, apathy, and progressive cognitive decline, which led to her death 2 years later. The differential diagnosis, neuroimaging, and pathological findings are discussed, as well as their public health implications.